The present invention relates to a method of measuring a harvested product quantity, which is supplied to an elevator of an agricultural machine from below and which is transported upwardly by the elevator in a transporting direction, and then at the upper side is thrown from the elevator and/or stored in it.
During harvesting with harvesters of the above mentioned type, for example harvester threshers, an exact control of each instantaneously harvested harvesting product quantity is needed in order to guarantee an efficient use of the harvester and to timely take into consideration corresponding disturbances. Moreover, it is necessary to determine the received harvested product in a time interval, for example a day or an operational hour, for example in order to provide computations of dependent on the quantity during the labor work. Furthermore, it is possible to produce an accurate harvesting cadastre.
The German patent document DE 31 24 35 A1 discloses an agricultural harvester, in particular a harvester thresher, in which the harvested product is loaded from a co-movable container over an elevator or a conveyor in an available motor vehicle or a trailer. During the loading process the weight or the harvested product quantity is weighed by a continuous scales at the harvested product inlet and at the outlet of the elevator. Alternatively, it is proposed to count the revolutions of a filled emptying screw and in this manner to determine the loaded harvested product quantity.
For continuous measurement of the harvested product during the harvesting it is known to determine the harvested product quantity capacitatively during its passage through a capacitor arrangement located for example behind the elevator outlet. The disadvantage of this measuring method is that the different moisture in the measuring chamber falsifies the measuring results, so that a continuous calibration is necessary. Furthermore, the electrodes in the measuring chambers are damaged by the passing harvested product, so that these measuring devices are very maintenance-intensive.
In addition to the above mentioned problems, these methods involve very high measuring-, compensation- and computing expenses.